Video framerate, resolution and grayscale tradeoffs for undersea telemanipulator

The product of Frame Rate (F) in frames per second, Resolution (R) in total pixels and grayscale in bits (G) equals the transmission band rate in bits per second. Thus for a fixed channel capacity there are tradeoffs between F, R and G in the actual sampling of the picture for a particular manual control task in the present case remote undersea manipulation. A manipulator was used in the MASTER/SLAVE mode to study these tradeoffs. Images were systematically degraded from 28 frames per second, 128 x 128 pixels and 16 levels (4 bits) grayscale, with various FRG combinations constructed from a real-time digitized (charge-injection) video camera. It was found that frame rate, resolution and grayscale could be independently reduced without preventing the operator from accomplishing his/her task. Threshold points were found beyond which degradation would prevent any successful performance. A general conclusion is that a well trained operator can perform familiar remote manipulator tasks with a considerably degrade picture, down to 50 K bits/ sec

Dispersion relations for circular single and double dusty plasma chains

We derive dispersion relations for a system of identical particles confined in a two-dimensional annular harmonic well and which interact through a Yukawa potential, e.g., a dusty plasma ring. When the particles are in a single chain (i.e., a one-dimensional ring) we find a longitudinal acoustic mode and a transverse optical mode which show approximate agreement with the dispersion relation for a straight configuration for large radii of the ring. When the radius decreases, the dispersion relations modify: there appears an anticrossing of the modes near the crossing point resulting in a frequency gap between the lower and upper branches of the modified dispersion relations. For the double chain (i.e., a two-dimensional zigzag configuration) the dispersion relation has four branches: longitudinal acoustic and optical and transverse acoustic and optical.Comment: 10 pages, 8 fugure

The transmission of nosocomial pathogens in an intensive care unit: a space–time clustering and structural equation modelling approach

We investigated the incidence of cases of nosocomial pathogens and risk factors in an intensive treatment unit ward to determine if the number of cases is dependent on location of patients and the colonization/infection history of the ward. A clustering approach method was developed to investigate the patterns of spread of cases through time for five microorganisms [methicillin-resistant Staphylococcus aureus (MRSA), Acinetobacter spp., Klebsiella spp., Candida spp., and Pseudomonas aeruginosa] using hospital microbiological monitoring data and ward records of patient-bed use. Cases of colonization/infection by MRSA, Candida and Pseudomonas were clustered in beds and through time while cases of Klebsiella and Acinetobacter were not. We used structural equation modelling to analyse interacting risk factors and the potential pathways of transmission in the ward. Prior nurse contact with colonized/infected patients, mediated by the number of patient-bed movements, were important predictors for all cases, except for those of Pseudomonas. General health and invasive surgery were significant predictors of cases of Candida and Klebsiella. We suggest that isolation and bed movement as a strategy to manage MRSA infections is likely to impact upon the incidence of cases of other opportunist pathogen

Assessing Effective Attributes Of Followers In A Leadership Process

Followership, being an understudied concept, raises fundamental questions: How did followership develop? Why do people submit into becoming followers? The developmental trajectory for the development of individual attributes is as yet, uncharted. Current study provides an overview of assessed attributes of followers, as proposed by Antelo (2010). Statistical survey design and correlation procedures are applied to assess selected variables and their relationship when examining the results of a multicultural survey conducted among leaders and followers in Russia, Belarus, United States, Bolivia, Mexico and Italy, totaling in over 400 members. Findings indicate that individual worker motivation influences performance and productivity.  Results of the study also illustrate that leaders typically rate themselves higher than followers do. The study discusses the need to understand how individual traits are developed, discovered, and how individuals can be formed, nurtured and prepared to become effective leaders as well as effective followers. The criticality of certain attributes characteristic to both leaders and followers is examined along with the need to analyze how some attributes can be changed.  Evolutionary approach in personal development and formation of individual attributes is taken into a great consideration.   &nbsp

Assessing Effective Attributes Of Followers In A Leadership Process

Followership, being an understudied concept, raises fundamental questions: How did followership develop? Why do people submit into becoming followers? The developmental trajectory for the development of individual attributes is as yet, uncharted. Current study provides an overview of assessed attributes of followers, as proposed by Antelo (2010). Statistical survey design and correlation procedures are applied to assess selected variables and their relationship when examining the results of a multicultural survey conducted among leaders and followers in Russia, Belarus, United States, Bolivia, Mexico and Italy, totaling in over 400 members. Findings indicate that individual worker motivation influences performance and productivity.  Results of the study also illustrate that leaders typically rate themselves higher than followers do. The study discusses the need to understand how individual traits are developed, discovered, and how individuals can be formed, nurtured and prepared to become effective leaders as well as effective followers. The criticality of certain attributes characteristic to both leaders and followers is examined along with the need to analyze how some attributes can be changed.  Evolutionary approach in personal development and formation of individual attributes is taken into a great consideration.   &nbsp

Finite-key security against coherent attacks in quantum key distribution

The work by Christandl, K\"onig and Renner [Phys. Rev. Lett. 102, 020504 (2009)] provides in particular the possibility of studying unconditional security in the finite-key regime for all discrete-variable protocols. We spell out this bound from their general formalism. Then we apply it to the study of a recently proposed protocol [Laing et al., Phys. Rev. A 82, 012304 (2010)]. This protocol is meaningful when the alignment of Alice's and Bob's reference frames is not monitored and may vary with time. In this scenario, the notion of asymptotic key rate has hardly any operational meaning, because if one waits too long time, the average correlations are smeared out and no security can be inferred. Therefore, finite-key analysis is necessary to find the maximal achievable secret key rate and the corresponding optimal number of signals.Comment: 9 pages, 4 figure

Fatigue Life Predictions of Additively Manufactured Components for Satelite Structures

The fatigue life properties of Additive Manufactured (AM) components are limited due to the defects naturally generated from the AM Process. For limited design life problems the finite fatigue life El-Haddad model linked defect size, applied stress, and design life. This paper developed a method to predict the smallest defect of interest for a given load case and the lowest failure generating stress for a given defect size. Experimental testing validated the method steps. The model was adjusted to demonstrate the space utility based on a 12U CubeSat chassis. Applying the design life and expected load, the finite fatigue life El-Haddad model predicted the minimum defect size for two configurations of the 12U CubeSat. The minimum defect size defined the Non-Destructive Evaluation (NDE) criteria for component certification. Combining the worst case potential defect size with the design life, the finite fatigue life El-Haddad model defined a minimum stress to generate failure. Linking the minimum stress value to the CubeSat Finite Element Model (FEM) predicted every location on the structure that could potentially fail due to the formation of AM defects. This second aspect defined the required inspection region to certify the structure for the given load case and design life